Are expensive wires and interconnects necessary

[Victor]

Further digression.....

Anyone hear(LOL) of Psychoacoustics?

It is important to note that the question of what humans hear is not only a physiological question of features of the ear but very much also a psychological issue - what we perceive or 'feel' we hear. For example, the ear itself does not respond to frequencies below 20Hz, but these can be perceived via the body's sense of touch.

Comments?

I am in the process of building a sub that will do more then 115 dB at 16 Hz in my room. Right now my dipole subs do 20 Hz at about 94 dB. It gets scary with Bach works that play often. My dog runs for cover. And I can feel music rather then hear. But I want more for the movies. I shall report on how the new sub feels when it is ready.

As for the psychoacoustics, I admit that I have absolutely no idea what it is. I am not sure if you can measure the psychoacoustic effects in any reliable fashion. Perhaps statistically, - well, I don’ really know.

In my opinion, - if you can’t measure it then it is opened to a subjective evaluation with ‘all bets are off’ attitude. I tend to see audio as a science only; - therefore measurement is the only tool applicable for evaluation purposes.

Victor

[Eliav]

I am in the process of building a sub that will do more then 115 dB at 16 Hz in my room. Right now my dipole subs do 20 Hz at about 94 dB. It gets scary with Bach works that play often. My dog runs for cover. And I can feel music rather then hear. But I want more for the movies. I shall report on how the new sub feels when it is ready.

As for the psychoacoustics, I admit that I have absolutely no idea what it is. I am not sure if you can measure the psychoacoustic effects in any reliable fashion. Perhaps statistically, - well, I don’ really know.

In my opinion, - if you can’t measure it then it is opened to a subjective evaluation with ‘all bets are off’ attitude. I tend to see audio as a science only; - therefore measurement is the only tool applicable for evaluation purposes.

Victor

The human ear cannot hear lower than 20Hz, below these frequencies, if the signal is loud enogh it would be percievd as a vibro-tactile one, the skull and our soft tissues will vibrate in a way that we evetually FEEL the vibrations, not hear them, this can be easily proven with barin-evoked potentials which will prove no activity in the acoustic cortex.
Psychoacoustics is the emotional- subcortical reaction to sound/music. the best example I can think about is listening fatigue. something "there" ( probably thalamus) tells you that this is not "it" = you got to turn the volume down or stop listening.
Eliav

[Chris D]

Vincent, Eliav has got it right. I too am fascinated by psychoacoustics, but you have to keep that separate from what you're talking about with bass. The human body's ability to FEEL sound waves is tactile sensation. Psychoacoustics is the phenomenon of the human mind altering the perception of the sound that the ear receives.

Prime examples are as mentioned above: psychoacoustics often makes people perceive that between low bass frequencies and higher treble frequencies played at the same volume, that the bass freqs sound quieter. This leads to people building in "house curves" into their system equalization to steadily increase the volume as the system produces lower and lower frequencies.

Tactile sensation is FEELING bass sound waves vibrate your clothes, floor, seating, etc, even when it is below your physical ear hearing threshold. Interestingly enough, you can even "hear" sounds that are not audibly broadcast through air sound waves, if they are physically transmitted to your eardrum through physical tactile vibrations.

[Alloroc]

Vincent, Eliav has got it right. I too am fascinated by psychoacoustics, but you have to keep that separate from what you're talking about with bass. The human body's ability to FEEL sound waves is tactile sensation. Psychoacoustics is the phenomenon of the human mind altering the perception of the sound that the ear receives.

Prime examples are as mentioned above: psychoacoustics often makes people perceive that between low bass frequencies and higher treble frequencies played at the same volume, that the bass freqs sound quieter. This leads to people building in "house curves" into their system equalization to steadily increase the volume as the system produces lower and lower frequencies.

Tactile sensation is FEELING bass sound waves vibrate your clothes, floor, seating, etc, even when it is below your physical ear hearing threshold. Interestingly enough, you can even "hear" sounds that are not audibly broadcast through air sound waves, if they are physically transmitted to your eardrum through physical tactile vibrations.

You are correct of course, about tactile sensation and the feeling of soundwaves.

However, understanding how these waves are received and mapped into thoughts in the brain is complex and, well, scientific.

This is exactly what the study of Psychoacoustics and Psychophysiology for that matter is all about.

Or, in other words, it is the study of psychology of acoustical perception. An interconnection exists between physics and psychology of hearing.

This includes how we listen, our psychological responses, and the physiological impact of music and sound on the human nervous system. In the realm of psychoacoustics, the terms music, sound, frequency, and vibration are interchangeable.

The study of psychoacoustics dissects the listening experience. It's not just about how loud we percieve a sound to be.

Can you hear any difference between a 100Hz and 101Hz sine tone? If you heard a 100Hz sine tone and a 100Hz trombone tone, would you perceive them as having the same pitch? How would you evaluate the relative pitch of a soft 100Hz tone, and a loud 100Hz tone? If a somewhat soft tone, and then 10 milliseconds later a somewhat louder tone were sounded, how many tones would you hear? Do right-handed people hear sounds the same as lefties?

The reason why this is relevant to the world of HiFi, is how manufacturers and their software developers apply their knowledge of Psychoacoustics to the delvelopment of how they produce recorded music and equipment that stimulates our listening experience psychoacousticly. For example, various Dolby formats, DTS, PCM, MP3, MLP and other MPEG layer formats employed Psychoacoustics in their development.

It's not all about the electronics!

Who ever thought we'd end up here!

[Shawn Parr]

If a somewhat soft tone, and then 10 milliseconds later a somewhat louder tone were sounded, how many tones would you hear?

Actually this is a very cool effect, and it is referred to as the Haas effect.

To really simplify it, when you hear two sounds close together that are exactly, or almost exactly the same, the amount of time between the two events can radically change the way your brain interprets it.

If they are less than about 10ms, then your brain interprets them as either being the same, or the louder one being the source.

Around about 20ms or so your brain starts to assume the first one was the source, even if it is much quieter (in some cases even if you normally wouldn't hear it due to masking). Your brain basically assumes that the louder sound is early reflections from the walls, and consciously you only hear the one sound.

After that range (IIR about 30ms) you start to really hear two distinct sounds.

We use this a lot in sound systems, especially musical theatre. A typical setup will have sound from the speakers reaching the audience louder and earlier than the actors natural voices. By using a system delay, we can overdelay slightly and you can hear a point where the sound system seems to disappear and the actors voices just seem to become very present in the room. Go a little too short or a little too long with the delay and the effect is completely lost.

[Chris D]

Now THIS is cool stuff... why don't we start another thread on psychoacoustics? I think it's fascinating that different types of sound can change significantly how the human brain perceives it.

It's true, you can't just go off the mathematical numbers of something, it comes down to how we humans hear it!

[RobP]

I would have to agree with you Chris, there is much to say about sound frequencies that we cannot hear and how they can affect the minds image of what we are hearing. Not only can low bass play into this realm but so can high frequencies. We can feel changes in air pressure that cannot be measured or explained. A good example is like how you can feel another persons presence in the room even though you did not hear them walk in or see them.

[Eliav]

I would have to agree with you Chris, there is much to say about sound frequencies that we cannot hear and how they can affect the minds image of what we are hearing. Not only can low bass play into this realm but so can high frequencies. We can feel changes in air pressure that cannot be measured or explained. A good example is like how you can feel another persons presence in the room even though you did not hear them walk in or see them.

I think I do have an explanation for this !
You probably DO hear them, as you also hear so many unimportant things around you all the time, the interesting thing is WHICH auditory information finally makes it to your cortex and "intrude" your concsiousness. we hear tons of "garbage" information every minute this is all being filtered in subcortical levels so that our consious "ignores" them, only "important" information will go through, such as the presence of another person in our vicinity (fight or flight reflex?). the reason you thought you "did not hear" them coming in to the room is because your brain ignored the information until something drew its attention to it .
Same things happen with our visual system, we see too many things that if went through our upper levels- it would have overwhelmed the system so we are actually "cortically blind" to them. There are some alarms that will alert the system to a visual stimulus even if it was caught in a glimpse, such as a snake or snake shaped object, you system will ALERT the "concsious" and that "thing" will not be ignored ( again, survival reflex that is programmed in our brain stem !).

I hope it helps
Eliav

[tnt]

"If you have an AP-3 system, then this filter is built-in. It is a very steep FIR filter with absolute minimum ringing. Its -3dB point is at 20 kHz. When using it you must consider that this filter will cut the signal level at 20 kHz to the 70% of what the level is at about 16 kHz. This will be audible when you compare the sound when no filter is used. In itself this does not show that our ears are sensitive to the ultrasonic frequencies." - Victor

That's a good trick I didn't think about. AES17 filter is a brickwall at 22kHz. I'll just put AP system 3 in series with the source and have fun testing my belief human ears perceive ultrasonic frequencies even we don't actively hear single tone above 20kHz (or lower freq. depending on age and gender). The 3dB attenuation at 17kHz won't matter for most people, theoretically, as they don't hear over that frequency in single tones.

Of course I do know the prerequisites for ABX testing including same SPL. The main difference in amps all can hear is the soundstage due to spatial information in a stereo program. I claim that high end amps should be able to reproduce ultrasound so that they can faithfully restore spatial info, with which we perceive soundstage. Cymbals (and percussion instuments) have harmonics over 100kHz.

BTW what were your impressions at the "digital amp show-down". The official write-up is too PC and showed that some UcD-based amps are not that good sonically, which surprises me.

[bigburner]

Next, the objectivist view does not allow for the immature state of our measurement technology.

Hi Sparky,

Firstly apologies for the delay in replying. I've been a busy boy recently.

The issue I have with this particular argument is best addressed by my old chum Professor Robert L. Park's third warning sign of bogus science:

3. The scientific effect involved is always at the very limit of detection. Alas, there is never a clear photograph of a flying saucer, or the Loch Ness monster. All scientific measurements must contend with some level of background noise or statistical fluctuation. But if the signal-to-noise ratio cannot be improved, even in principle, the effect is probably not real and the work is not science.

Thousands of published papers in para-psychology, for example, claim to report verified instances of telepathy, psychokinesis, or precognition. But those effects show up only in tortured analyses of statistics. The researchers can find no way to boost the signal, which suggests that it isn't really there.

I believe that our measurement technologies are much more advanced than you suggest. The reason that we can't measure the difference between one speaker cable and another is because there is no difference.

Regards,
Nigel.

PS. Lex, I just want to let you know that my comments are made in a non-belligerent, non-confrontational way.

[DifferentLee]

I have found that better cables do make a difference. I worked on an album in the mid-90s when we had some donations from Cardas cable on mic cable. We have been using Mogami which is decent but it was amazing how much open the sound got when we put in Microtwin cable from Cardas. I still work part-time as a "live to 2 track" engineer.

A few years later I installed Cardas Golden Reference in my home stereo and that really elevated its performance.

I have also found that measurements are not very good at capturing the whole audio recording or playback experience. With respect to cables, it can be valuable to have the numbers on inductance, capacitance, and resistance but the real proof is in the listening. You want to listen to resolution, tonality and imaging primarily.

[JonMarsh]

The Cardas cables do measure quite well, very low in resistance and inductance. I'm a fan of the Golden Reference series also. They wouuld certainly be overkill for many systems, but even a high quality dynamic two way will audition noticably better with them than compared with many other cables. And I'm rather an objectivist as well as an EE.

[DifferentLee]

The Cardas cables do measure quite well, very low in resistance and inductance.

George has an article on the Cardas website about cable metrics that is fascinating...

[Lex]

This is not going to become brand specific, I believe that was outlined previously, theory is not about brands.

[DifferentLee]

This is not going to become brand specific, I believe that was outlined previously, theory is not about brands.

What's the issue with talking about brands? Some are indeed better than others and in the case of Cardas, they present evidence directly on topic.

[Kobus]

Because I am the boss and I say so !!!!

(Sorry, I just had to.)